diff --git a/CHANGES.rst b/CHANGES.rst
index 1d4f80e0..6de5b0d0 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,6 +2,12 @@
  Changes
 =========
 
+4.0.0a2 (unreleased)
+====================
+
+- Nothing changed yet.
+
+
 4.0.0a1 (2023-06-30)
 ====================
 
diff --git a/version.txt b/version.txt
index a23faae1..9e736c7c 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-4.0.0a1
+4.0.0a2.dev0